In a communication switch, functionality is provided through a set of cards operating together to provide communication switching. Frequently, cards are grouped together in logical groups of shelves. Often for a shelf, or group of shelves, intelligent fan units are provided to maintain a safe operating ambient temperature for the components in the shelf. The fan units are controlled by remote controlling elements connected via links. However, prior art systems do not provide robust feedback to the controlling element of the fan unit regarding the operation of the fan. In the signalling connection from the fan to the controlling element, a failure in that link may cause a failure of the fan unit to go undetected by the controlling element. A similar problem exists with remotely controlled power modules in a switch.
There is a need for a system and method providing switching modularity that improves upon the prior art systems.